Plugging System For a Fuel Tank Filler Pipe

ABSTRACT

A system for plugging the top of a fuel tank filler pipe, including a stopper allowing the pipe to be opened automatically via action of a fuel dispensing nozzle. The stopper is retractable under action of a thrust directed against the stopper along an axis parallel to the axis of the top of the pipe, and is secured to a return spring keeping the stopper in the closed position. The system also includes a moving ring configured to prevent movement of the stopper via a bayonet system, and in which the movement of the bayonet system between opened and closed (or vice versa) is governed by a specific actuator and includes a progressive helical movement that progressively compresses (or decompresses) a seal affixed between the stopper and the top of the pipe.

The present invention relates to a system for plugging a fuel tank filler pipe.

Filler pipes present on fuel tanks, particularly tanks on board motor vehicles, are plugged during normal use of the tank, outside of filling periods. Plugging is generally achieved by means of a cap inserted into the upper part of the pipe, by having a rotational movement imparted to it in order to seal the pipe against liquids and gases. Various types of cap may be encountered, made of metal and/or made of plastic, sealing being achieved by compressing a seal, this being achieved by screwing or by turning a key inserted into the middle of the part outside the pipe.

The operations of removing the cap before filling the tank and of replacing this cap and closing off the pipe after filling are usually done manually by the user or by the service station attendant dispensing the fuel. When the tank filling operation is over, the replacing of the cap is sometimes forgotten and this can then give rise to the loss of this cap and to the pipe being left open to the atmosphere for some length of time. During this period, losses of liquid fuel may occur and vapours escape into the ambient atmosphere.

With a view to avoiding cap losses and the ensuing atmospheric pollution, plugging systems incorporated into the filler pipe have been proposed as a replacement for the conventional cap. Improved versions thereof generally comprise immobilizing means that prevent the said systems from opening unexpectedly, for example when the bowl (the depression in the bodywork in which the filler pipe is located and which is closed off by the fuel filler flap) is being cleaned using a pressure washer.

Thus, for example, application WO 03/010022 in the name of the Applicant Company describes a plugging device equipped with immobilizing mean that can be disengaged by a thrust force parallel to the axis of the top of the pipe and re-engaged automatically when the fuel filler flap is closed. A system such as this has the advantage of automatic locking, coupled with the closing of the filler flap, and of working even if there is a failure in the electrics of the vehicle (since disengagement is manual) via the thrust from the nozzle. However, it does present the risk that a high pressure water jet directed substantially parallel to the axis of the top of the pipe can, in spite of everything, disengage the immobilizing means just as a filler nozzle would. Furthermore, the particular system illustrated in this application (bayonet system including a hairpin spring, a linkage, a rotary collar, two springs, etc.) is complicated.

A simpler system that solves the aforementioned disadvantage of unexpected opening is described in application EP 2004/052156 in the name of the Applicant Company also. That system comprises:

-   -   a lever secured to the plugging mechanism and having the effect         of locking/unlocking it depending on its position;     -   a lever arm secured to the fuel filler flap which can actually         act on the lever only in order to lock the mechanism when         unlocked and when the fuel filler flap is closed.

In that application, variants involving bayonet fittings are illustrated, these being relatively simple and involving a pure and simple rotational relative movement of the two complementary parts of the device. However, the Applicant Company has found that such a system could lead to defective sealing.

More sophisticated systems have also been put forward, making it possible both to solve the problem of sealing and the problem of unexpected opening, but through recourse to devices that are often complex. Thus, for example, there are such things as “capless” tops on the market that include a pivoting flap kept closed by a (main) spring rated in such a way that the force required to overcome this spring force is high enough to prevent unexpected opening. In order to allow the shutter to open as a result of the manual thrust of the user using the nozzle in spite of this, without damaging the said shutter, these heads comprise a second (secondary) spring, with a lower spring rate, that imposes the correct position upon the nozzle (see, for example, application FR 2 753 138). Finally, in order to prevent the nozzle from remaining jammed in the top of the pipe given the return force of the main spring, these devices are also often equipped with a retarder, for example like the one described in application EP 46886. Such a system is therefore extremely complicated and expensive.

The present application is therefore aimed at providing a simple, low-bulk “capless” system that solves both the problem of sealing and that of unexpected opening.

For this purpose, the present invention relates to a system for plugging the top of a fuel tank filler pipe, the said system comprising a stopper allowing the pipe to be opened automatically via the action of a fuel dispensing nozzle, this stopper being:

-   -   retractable under the action of a thrust directed against it         along an axis parallel to the axis of the top of the pipe;     -   secured to a return spring keeping it in the closed position;         the said system also comprising a moving ring able to prevent         the movement of the stopper via a bayonet system, and in which         the movement of the bayonet system between opened and closed (or         vice versa) is governed by a specific actuator and consists of a         progressive helical movement that progressively compresses (or         decompresses) a seal affixed between the stopper and the top of         the pipe.

Such a system does actually make it possible to solve:

-   -   the problem of unexpected opening, by recourse to a specific         actuator which governs the opening of the bayonet system;     -   the problem of sealing by virtue of the presence of the seal         affixed between the stopper and the top of the pipe, and by         virtue of the fact that this seal is compressed progressively         during the closing movement of the bayonet; such progressive         compression reduces the closure forces and, in doing so,         improves the durability of the system;     -   the problems of complexity and of cost; specifically, the         presence of the bayonet mechanism and of the seal makes it         possible to reduce the return force of the main spring and         therefore to dispense with the retarder used in the         sophisticated solutions described hereinabove.

The term “fuel tank” is intended to denote any type of tank capable of storing a liquid and/or gaseous fuel under varying temperature and pressure conditions. Those more particularly concerned are tanks of the kind found in motor vehicles. The expression “motor vehicle” is intended to include motor cars, motorcycles and trucks.

The filler pipe is a pipe which communicates with the inside of the tank and allows fuel to be introduced.

The tank and the pipe may be made of metal or of plastic.

The plugging system according to the invention is well-suited to a tank and filler pipe assembly in which at least one of the two components of the assembly is made of plastic. It is particularly well-suited to an assembly in which the filler pipe is made of plastic. As a preference, this plugging device itself comprises at least one part made of plastic. As a quite particular preference, it is mainly made of plastic.

The term “plastic” is intended to denote any material comprising at least one synthetic resin polymer.

All types of plastic may be suitable. Particularly suitable plastics come from the thermoplastics category.

The term “thermoplastic” denotes any thermoplastic polymer, including thermoplastic elastomers, as well as blends thereof. The term “polymer” denotes both homopolymers and copolymers (especially binary or ternary copolymers). Examples of such copolymers are, nonlimitingly, random copolymers, linear block copolymers, other block copolymers and graft copolymers.

Any type of thermoplastic polymer or copolymer whose melting point is below the decomposition temperature is suitable. Synthetic thermoplastics that have a melting range spread over at least 10 degrees Celsius are particularly suitable. Examples of such materials include those that exhibit polydispersion in their molecular weight.

In particular, polyolefins, polyvinyl halides, thermoplastic polyesters, polyketones, polyamides and copolymers thereof may be used. A blend of polymers or copolymers may also be used, as may a blend of polymer materials with inorganic, organic and/or natural fillers such as, for example, but nonlimitingly, carbon, salts and other inorganic derivatives, natural fibres or polymeric fibres. In particular, fibre-filled (for example glass-fibre-filled) polyamides are particularly suitable. Advantageously, at least some of these polymeric materials contain a conductive filler (carbon black, for example) in order to avoid problems associated with static electricity. It is also possible to use multilayer structures consisting of stacked layers bonded together comprising at least one of the polymers or copolymers described above.

The plugging system according to the invention is intended to act as a cap which seals the upper part of the filler pipe, outside periods when the tank is being filled, with a view to avoiding any release and loss of liquid fuel and vapour into the atmosphere when the tanks contains fuel.

For preference, the plugging system according to the invention is incorporated into the top of the filler pipe, that is to say is incorporated into a set of parts which are mounted on the upper end of the filler pipe and the purpose of which is to guide a fuel dispensing nozzle and make filling easier. To do this, the top of the pipe comprises an opening communicating with (in the continuation of) the filler pipe and that the stopper of the system according to the invention is able to close off in a sealed manner when in the closed (locked) position.

The plugging system according to the invention in particular allows the pipe to be opened automatically via the action of the filler nozzle. The expression “opened automatically” is to be understood as meaning opening performed simply under the action of the dispensing nozzle, to the exclusion of any other mechanical influence. The dispensing nozzle is the one fitted to the fuel pump hoses in service stations.

The plugging system comprises a stopper, that is to say a device that closes off the passage to gases and liquids through the aforementioned opening in the top of the pipe. This stopper may adopt various forms. One particularly suitable form is that of a moving plate which plugs the passage when in the closed position. As a preference, this plate pivots about an axis. It is advantageously made of plastic but is preferably equipped with a metal cover, particularly for aesthetic reasons and for resistance to abrasion (wear following numerous insertions of filler nozzles).

This plate may possibly be coupled to a rotary plug comprising a cylindrical opening (as in application FR 03/12782 in the name of the Applicant Company, the content of which is therefore incorporated by reference into this application).

This plate may also comprise a device for regulating the pressure in the filler pipe and, in particular, an “SPD” (for “safety under pressure and depression”) valve as described in application FR 2 753 138, the content of which is also incorporated by reference into this application.

According to the invention, the stopper can retract under the action of a thrust directed against it along an axis parallel to the axis of the top of the pipe. Various means may be present to render the stopper retractable. One means that has yielded good results is a rod secured to the top of the pipe and situated at the periphery of the stopper, which can act as a rotation axle allowing the stopper to pivot.

The stopper is kept in a closed position by a return spring. One type of spring that is particularly suitable is a torsion spring positioned around the rod and one end of which is secured to the stopper.

The stopper can present a conical shape on the part suitable to cooperate, when the stopper is in closed position, with the periphery of the opening in the top of the pipe. In general, the conical geometry allows a reduction of the stopper closing force and the use of less powerful springs.

According to the invention, the stopper is secured to a moving ring by a bayonet system of which the collaborating parts are preferably located on the interior cylindrical surface of the ring and on the periphery of the stopper, respectively. These parts of the bayonet device need to have a geometry such that it allows a gradual helical movement of the ring between the positions in which the bayonet is locked and unlocked. Thus, for example, one part (for example, the ring) may comprise recesses of an appropriate size and shape to allow the lugs located on the other part (the stopper) to pass and move. The rotary ring may be made of plastic (as defined hereinabove) or of metal.

In particular, the recesses in the ring (or in the stopper) advantageously comprise a helical ramp and notches in a number corresponding to the number of lugs positioned on the stopper (or on the ring). These lugs/notches are generally positioned uniformly on the periphery of the ring and of the stopper and are generally at least two, preferably three, or even four, or even six in number. Systems involving three lugs/notches yield good results.

The variant whereby the stopper bears the lugs and the ring bears the recesses is preferred. Note, for example, that existing tops of pipes may in this way easily be equipped with a device according to the invention. Indeed, all that is required is for the existing stopper to be provided with a shield bearing lugs, for a seal to be inserted between this shield and the top of the pipe and for a moving ring with recesses as described hereinabove to be fixed over the top of all of this.

In consequence, the present invention also relates to a method for the sealed locking of the top of a fuel tank filler pipe comprising a stopper allowing the pipe to be opened automatically via the action of a fuel dispensing nozzle, this stopper being:

-   -   retractable under the action of a thrust directed against it         along an axis parallel to the axis of the top of the pipe;     -   secured to a return spring keeping it in the closed position;         the said method consisting in equipping the stopper with a         shield bearing lugs at its periphery, in possibly inserting a         seal between the said shield and the top of the pipe and in         fixing, over the top of all this, a moving ring equipped with a         helical ramp and with notches, the shape, number and location of         which correspond to those of the lugs on the stopper.

Alternatively, the said method may consist in equipping the stopper with a shield bearing lugs at its periphery, in inserting between the said shield and the top of the pipe a mobile ring equipped with a helical ramp and with notches, the shape, number and location of which correspond to those of the lugs of the stopper, and in fixing this assembly onto the top of the pipe by welding on at least one add-on part. This add-on part may, for example, be a ring flange. Note that, as a variant, the shield may be equipped directly with lugs and that, in this case, the moving ring is inserted directly under these lugs.

In such systems, when the bayonet is in the locked position, the recesses are engaged with the ramp and immobilize the stopper (thrust along the axis not allowing it to pivot). When the bayonet fitting is opened, the ring is given a helical movement which is, in fact, a combination of a rotational movement about the axis of the stopper (for example, describing at least ⅛, even ⅙ and preferably at least ¼ of a turn (this fraction being, in fact, dependent on the number of lugs)) and of a translational movement parallel to this axis (for example, of the order of a few 1/10 of an mm, or even of 1 mm, depending on the nature of the seal (so that it is compressed enough to provide the desired level of sealing)). As a result, the lugs travel along the ramp (or vice versa, in fact, since the lugs are stationary) until they reach the notches made in the ramp for that purpose and thus allow the stopper to pivot.

One important characteristic of the system according to the invention is the presence of a seal fixed between the stopper and the top of the pipe or, more precisely, around the periphery of the opening therein that the stopper is supposed to plug. The aforementioned ring helical movement needs to be such that it allows this seal to be compressed as the bayonet is closed and decompressed as it is opened, respectively. This seal may be of any kind. A seal of the O-ring type yields good results. The material of which this seal is made will preferably need to be chosen such that it is resistant to fuel vapours. Fluorinated elastomers are particularly suited to this purpose.

In the case where the stopper presents a part with a conical shape profile, the sealing between this profile and the profile of the periphery of the opening in the top of the pipe, can be made by a seal with an adapted geometry, for example a spindle seal.

Finally, another important characteristic of the invention is in recourse to an actuator which has to be activated specifically in order to allow the ring to move. Any type of actuator is suitable for this. It may, for example, be a “manual” actuator (lever, cable, ignition key, etc.). It may also be an automatic actuator (mechanical (motor), electric or pneumatic).

The present invention finally relates to a motor vehicle equipped with a plugging system as described previously.

Preferably, this vehicle is provided with a monitoring sensor (a luminous or audible indicator) to check that the plugging system is correctly locked, and this sensor may advantageously be incorporated into the vehicle cabin, to improve safety.

For the same reason (safety), it is also possible to choose to employ, on this vehicle, a plugging system in which the actuator can be activated only using the ignition key.

An example of such a system is one where the ring of the bayonet fitting is driven by a set of gears set in rotation by a barrel under the action of the vehicle ignition key. Turning the key by a quarter of a turn, for example, unlocks the bayonet, which then allows the stopper to pivot. When the bayonet is in the unlocked position it is preferably (in such a system) impossible to remove the key from the barrel. This key cannot be removed until, by being turned a quarter of a turn in the opposite direction using the key, the bayonet is locked. This device secures access to the head filling orifice while guaranteeing that the vehicle cannot be restarted unless the top of the pipe is locked and secured (acting as an anti-theft cap).

The present invention is illustrated nonlimitingly by FIGS. 1 and 2.

FIG. 1 depicts a section through a fuel filler flap (1) (the door in the bodywork) and the top (2) of a fuel tank filler pipe equipped with a plugging system according to a variant of the invention.

FIG. 2 is an enlarged view of the part encircled in FIG. 1.

The top depicted in these figures is fitted with a stopper (3) comprising an SPD valve (4), as in the aforementioned FR application (see also the text of that application for further details on the way in which such a stopper works). This stopper can move by pivoting about an axis (5) secured to the top of the pipe (2) and about which a return spring (6) that serves to keep the stopper in a normally closed position (the position illustrated in the figure) is wound.

The stopper (3) is equipped with a shield (7) comprising lugs (7′) and between the periphery of the shield (7) and the upper part of the top of the pipe (2′) a rotary ring (8) equipped with a helical ramp and with notches (not illustrated in the figures) has been inserted. The lugs (7′) of the shield (7) have a shape, size and location such that they are able to collaborate with the notches of the rotary ring (8) and with recesses (12) in the upper part of the top of the pipe (2′) so that when the bayonet mechanism (consisting of the pairing of the shield equipped with the lugs and the rotary ring equipped with notches) is in the open position the stopper can pivot under the action of an axial thrust exerted by the filler nozzle.

The shield (7) and the ring (8) are fixed to the top of the pipe (2) by means of a ring flange (9) welded to the said top of the pipe (2).

The rotary movement of the ring (8) is brought about by a specific actuator of which only the actuating rod (10), secured to the ring (8), has been illustrated. The rotary movement of the ring causes a helical movement of the shield (7) since the said ring (8) is equipped with a helical ramp. Upon opening, this helical movement is downwards, so as to relieve the load on a seal (11) affixed between the stopper (3) and the upper part of the top of the pipe (2′). Upon closure, the helical movement is upwards, so as to compress the seal (11).

The system is depicted in the closed position, shield (7) and stopper (3) upward, seal (11) compressed. 

1-10. (canceled)
 11. A system for plugging the top of a fuel tank filler pipe, the system comprising: a stopper allowing the pipe to be opened automatically via action of a fuel dispensing nozzle, the stopper being: retractable under action of a thrust directed against the stopper along an axis parallel to the axis of the top of the pipe; secured to a return spring keeping the stopper in a closed position; and a moving ring configured to prevent movement of the stopper via a bayonet system, and in which movement of the bayonet system between opened and closed, or vice versa, is governed by a specific actuator and includes a progressive helical movement that progressively compresses or decompresses a seal affixed between the stopper and the top of the pipe.
 12. The system according to claim 11, wherein the stopper includes a moving plate pivoting about an axis.
 13. The system according to claim 12, wherein the plate is made of plastic and includes a metal cover.
 14. The system according to claim 12, wherein the plate includes a device for setting the pressure in the filler pipe.
 15. The system according to claim 11, further comprising a rod, secured to the top of the pipe, situated at a periphery of the stopper and allowing the stopper to pivot, the rod including a torsion spring having one end secured to the stopper and that keeps the stopper in the closed position.
 16. The system according to claim 11, wherein the stopper includes lugs and the moving ring includes a helical ramp and notches, a shape, number, and location of the notches correspond to those of the lugs on the stopper.
 17. A method for sealed locking of the top of a fuel tank filler pipe including a stopper allowing the pipe to be opened automatically via action of a fuel dispensing nozzle, the stopper being: retractable under action of a thrust directed against the stopper along an axis parallel to the axis of the top of the pipe; and secured to a return spring keeping the stopper in closed position, the method comprising: equipping the stopper with a shield bearing lugs at its periphery, possibly inserting a seal between the shield and the top of the pipe; and fixing, over the top of all this, a moving ring equipped with a helical ramp and with notches, a shape, number, and location of the notches correspond to those of the lugs on the stopper.
 18. A method for sealed locking of the top of a fuel tank filler pipe including a stopper allowing the pipe to be opened automatically via action of a fuel dispensing nozzle, the stopper being: retractable under action of a thrust directed against the stopper along an axis parallel to the axis of the top of the pipe; and secured to a return spring keeping the stopper in a closed position; the method comprising: equipping the stopper with a shield bearing lugs at its periphery; inserting between the shield and the top of the pipe a mobile ring equipped with a helical ramp and with notches, a shape, number, and location of the notches correspond to those of the lugs of the stopper; and fixing the assembly onto the top of the pipe by welding on at least one add-on part.
 19. A motor vehicle equipped with a plugging system according to claim
 11. 20. The vehicle according to claim 19 and comprising a sensor for monitoring that the plugging system is correctly locked. 